Men are better navigators - but why?
Evolutionary hypotheses to explain differences - sometimes hard to swallow, as Brynja Adam-Radmanic experienced.
When it comes to navigation my husband and I are typical examples of our gender. He always finds the way back to the hotel in foreign cities. I admit a task that isn't that easy for me but until now I thought why be concerned about it. There's nothing to be ashamed of, we share this sex difference with a lot of our mammalian cousinship. In humans the male performs better in wayfinding by means of compass directions or geometrical information. In fact these abstract cues help men to take significantly less time to reach a destination than women. If these are the facts, I can just accept them and turn on the car's navigation system, when I believe I am getting lost.
However, the field of sex differences is a touchy one and I couldn't help taking the conclusions of a recent paper a bit personally but first things first. Actually the paper [1] is a piece of work that shows men remember the spatial location of objects much better than women, using what is commonly seen as the underlying mechanism of the male advantage in wayfinding. Women on the other hand rely on visual features for spatial tasks, even when these tasks can only be solved using spatial information. The authors were surprised to find that men didn't show preference for “their type of cue”, but remember spatial and visual attributes equally well.
The authors conclude that because male abilities seem to be quite balanced, we shouldn't ask what the adaptive value of male advantage is, like most researchers have done before. Instead the focus should be on the question of why women are selectivly blind in regards to the spatial eye. Their favourite explanation for this is the Female Fertility Hypothesis presented by Sherry [2], which assumes that selection has acted on women in reducing their spatial skill. The poorer navigation skills in women are seen as the reason that they stay at home preferentially, thus boosting their reproductive success.
Well, it's comforting to know that my children have a better chance of survival because I don't know where to find North. To be honest, how plausible and how annoying is that? I don't deny, that female hormones cause most women to reduce their mobility. However, I definitely don't like the idea, that it should be lack of ability that makes the average woman more domestic in their reproductive period.
I know we can't discuss evolutionary explanations for behavior on the level of personal experience. Following a second cooler look at the hypothesis, I even find the idea inspiring, that such seemingly useful skills as spatial memory could be negatively selected but for me to accept this, the Female Fertility Hypothesis needs to be fused with other hypotheses. Let's assume the mother's corrupt sense of orientation in fact enhances survival rates in her offspring. Why shouldn't this apply equally to men? Men who stay at home won't get themselves killed and they will have a lot more time to work on their mating success. Why shouldn't evolution favour this behaviour as well, by awarding them equally poor navigational skills?
When we go the whole way and conclude, that wayfinding may not be beneficial at all as a conclusion, the questions change to: Why do men have these spatial skills although they might lead to existential trouble? Why are men better at finding places in foreign cities although this is unfavoured by natural selection? Does that ring a bell? Well, there's only one plausible answer: female choice. Maybe spatial skill is something like the colourful coat of male birds: Attracting a great deal of attention is perilous - but females like it. Often to their own surprise women in fact choose men who show their prowess by going too fast with their cars or who have dangerous hobbies. To survive this, men are in desperate need of these spatial skills. That sounds much more convincing doesn't it? However, don't tell my husband! Why should he be inflicted by doubts about the usefulness of his skills? He must not know that the only reason he finds the way back to the hotel is to impress me. Sometimes a woman has to enjoy silently.
[1] Catherine M. Jones and Susan D. Healy, 2006
Differences in cue use and spatial memory in men and women
Proceedings of the Royal Society B: Biological Sciences
FirstCite Early Online Publishing
http://dx.doi.org/10.1098/rspb.2006.3572
[2] Sherry, D.G. 1997
Evolution and the hormonal control of sexually-dimorphic spatial abilities in humans.
Trends Cogn. Sci. 1, 50-56
http://dx.doi.org/10.1016/S1364-6613(97)01015-2
